Boring machine and method



E. ARP

BORING MACHINE AND METHOD Filed July 29, 1929 7 Sheets-Sheet 1 zi'orneys I verzfox" E. /?/7'' 9% July 19, 19320 E. A. ARP 1,868,440

BORING momma AND METHOD Filed July 29, 1929 7 Shets-Sheet 2 July 19, E RP 1,868,440

BORING MACHINE AND METHOD Filed July 29, 1929 7 Sheets-Sheet 3 Jul 19, 1932. R 1,868,440

BORING MACHINE AND METHOD Filed July 29, 1929 7 Shets-Sheet 4 July 19, 1932. R 1,868,440

BORING MACHINE AND METHOD Filed July 29, 1929 7 Sheets-Sheet 5 I n ve n July 19, 1932. E, A, ARP 1,868,440

- BORING MACHINE AND METHOD Fued July 29, 1929 '7 Sheets-Sheet 6 Aftt July 19, 1932. E. A. ARP 1,868,440

v BORING MACHINE AND METHOD Filed July 29, 1929 7 Sheets-Sheet 7 1 Inventor;

571/7/70. By MM Patented July 19, 1932 UNITED STATES EWALD A. ARP, F MINNEAPOLIS, MINNESOTA, ASSIGNOR, BY MESNE ASSIGNMENTS, TO

PATENT OFFICE VAN NORMAN MACHINE TOOL COMPANY, OF SPRINGFIELD, MASSACHUSETTS, A.

CORPORATION Application filed July 29,

My invention relates to machines for fin ishing the bore of cylinders. It relates more particularly to machines for use in connection with cylinders of automobile engines,

either to finish the bore of new cylinders 01' to refinish the bore of cylinders which have become uneven through use. An object of the invention is to provide a machine which will give a smooth and uniform finish to the bore of the cylinder making it unnecessary to follow up the cutting operation by a honing operation. The latter operation is objectionable since it fills the pores of the metal surface with particles of honing material. Another object is to provide a machine with a combined centering and following device the centering device locating a machine accurately in relation to the cylinder to be finished, and the same device so adjustable to conform itself to the finished portion of a cylinder as soon as a small portion of the upper end has been finished, thus becoming a non-rotating steady guide traveling longitudinallv in the cylinder bore directly back 5 of and adjacentto the cutter head, guiding said cuttef head uniformly for any depth cylinder. Another object is to provide the machine with means for firmly holdingit in place on the cylinder block, such means being secured within a cylinder adjoining the one which is being operated upon. Another object is to provide controlling elements in a machine enabling a cylinder to be finished in a fraction of the time required with machines now in common use. Another object is the provision of improved means for controlling and adjusting various elements entering into the combination constituting the machine in order to meet the varying exigencies of practical use in finishing various cylinders.

The full objects and advantages of my invention-will appear in connection with the detailed description thereof, and the novel features of my inventive idea will be particularly pointed out in the claims.

In the accompanying drawings which illustrate a practical embodiment of my invention. Fig. 1 is a side elevational'view of the machine with a small portion shown in sec- .BORING MACHINE AND METHOD 1929. Serial N0. 381,697.

tion. Fig. 2 is a view mostly in vertical section showing the machine secured in place on' a cylinder block. Fig. 3 is a view in section on the line 33 of Fi 2 taken on an enlarged scale. 4: heet 3) is a view in vertical section at right angles to Fig. 2 on an enlarged scale and showing the tool being set by means of a micrometer. Fig. 5 is a view in horizontal section on the line 55 of Fig. 4. Fig. 6 (Sheet 4) is a fragmentary view in vertical section corresponding to Fi 2 and showing the manner of centerlng wit relation to the cylinder which is to be finished. Fig. 7 is a view in horizontal section on the line 77 of Fig. 6. Fig. 8 is a detail sectional view showing the cutter head. Fig. 9

' (Sheet 5) is a view in horizontal section on the line 9-9 of Fig. 4 butwith the micrometer removed. Fig. 10 is a fragmentary view in vertical section showing the position of the cutting tool after the upper portion of a cylinder has been finished. Fig. 11 is a similar view showing the centering device positioned to form a bearing for the cutter shaft. Fig. 12 (Sheet 6) is a view in horizontal section on the line 12-12 of Fig. 1 and on an enlarged scale. Fig. 13 (Sheet 7) is a view in vertical section turned through an angle as compared with Fig. 2 and in section on the line-1313 of Fig. 14. Fig. 14 is a view in section on the line 1414 of Fig. 13. Figs. 15 to 21 are detail views illustrating parts associated with the centering device.

While in operation, the machine rests upon a cylinder block B containing a plurality of nut 26 is threaded upon the lower end of a.

bolt 30 which passes through the top of the 24 by a flanged ring 37 secured to the upper surface of the member 24. The socket member 32 is internally threaded to receive the lower end of a second bolt 36 having a head 38. This head may be adjusted to the proper height above the cylinder by turnin the bolt 36. With the head 38 properly a justed a shoe 40 is slid in place upon the cylin er block. The middle portion of this shoe has a slot 42 which receives the head 38., the lower portion of the slot being reduced to form shoulders 44 which engage under the head 38. The machine has a base 46 (see Fig. 2) containing a downwardly opening recess 48 whereby the base carrying the machine may he slid along the shoe 40. The front end of the shoe 40 has two ears 50 as shown in Fig.

i 12 through which bolts 52 are threaded.

When these bolts areturned down, the front end of the shoe 40 will be canted upwardly by the bolts pressing down on the base 46.

The slot 42 with shoulders 44 are also canted upwardly, engaging and pulling on the bolt head 38. This will cause fingers 53 on the shoe 40 (see Fig. 5) to move downwardly and create a downward pressure on the base 46.

The machine is thereby held firmly to the cylinder block at four points by pressure caused by the fingers 53 and the screws 52 in the shoe 40, all stresses and strains and possible distortion being confined to the shoe 40 so that the machine is held firmly to the cylinder without distortion for the finishing operation. Before this is performed, however, the cutting tool is set to cut the desired diameter in the cylinder, and furthermore, the shaft of thecutting tool is centered in the cylinder as will be explained later.

The base 46' carries an electric motor 54 which supplies power bothfor rotating the lower end. Slidable vertically in the bearing cutter shaft for feeding the cutter slowly and steadily through thecylinder being rebored.

The base also'carries a bearing post 96 having an enlarged bearing portion 94 at its post is a sleeve 88 which is prevented from rotating by -a rack 186 secured to the sleeve and engaging in a slot in the bearingpost. At the upper end of the sleeve is secured a bearing member 86, and at the lower end is a bearing member. 98, rotatable in which is a cutter shaft 84 suitably prevented from axial *mot'ron-.t -A gear case 66 is carried by the upper bearing member 8.6and rises and falls with the movement of the sleeve 88. An exfrom the gear 70 to the cutter shaft by a train of gears 72, 76, 78, 82, best shown in Fig. 2.

At the lower end of the cutter shaft 84 is secured a disk 100. A pivot 104 on this disk supports a tool carrier 102 which may be swung into the position of Fig. 5 in which it abuts ashoulder 106 or into the position ofFig. 9. The former position is assumed during adjustment of the cutter and during actual boring operations; the latter position; since it brings the point of the cutter nearer the axis of the cutter shaft, is usedwhen the cutter is being brought up idly through a just rebored cylinder. The cutter 110, preferably having a point of tungsten carbide brazed in place, is held in the carrier by a spring 112 which retains it frictionally during adjustment, and by screws 116 which clamp it firmly for cutting? The cutter is adjusted to size by a micrometer116, the screws 116 being accessible through a cut away portion 132 (Fig. 9) of the base while the device is mounted in place on the cylinder block.

A device will now be described by which the cutter bar can be centralized prior to the clamping of the machine to the cylinder block by the screws 52 and-by which the cutter is guided through the cylinder in a straight line during the cutting operation. By referring to Fig.- 13, it will be seen'that a vertical rod 134 is rotatably supported by the gear housing 66 and the member 94. Secured to the upper end of this rod, there is a knurled knob 136, the lower portion of which is provided with detent teeth 138 adapted to engage with detent teeth 140 as best shown in Fig. 1. As shown in Fig. 13, the detent teeth 140 are formed on the upper edge of a tubular member 142 fitting in a socket in .the gearhousing and held in place by a setscrew 144. The lower end of the rod .meshes with a ring gear 148 in such manner that the rod 134 is capable of a sliding movement suflicient for the detent teeth 138 and 140 to be disengaged from each other. The lower surface of the ring gear 148 is formed with teeth 150 out in. the form of a bevel gear which meshes with four bevel gears 152 arranged 90 from each other as shown in Fig.

7. The gears 152 work in connection with four guide members 154 respectively in order to feed said guide members outwardly when the rod 134 is turned in-a forward direction. The guide members 154 are'held for sliding movement radially in slots formedin a member 156 placed belowjthe member 922s will be seen from 4' and The operating connections between the gears 152 and the guide members 154 will be understood from the detail views shown in Figs. 15 to 21. As shown in Fig. 16, the gear152 has a hollow hub 158 which at its outer end is provided with a semi-circular flangelike portion 160 formed by cutting away the material at this end for half the circumference as indicated at 161. An internally threaded tube 162 having a head 164 extends through the hub 158 so that the head 164 is adjacent the gear 152. The end of the tube 162 opposite the head 164 is notched so as to produce two oppositely disposed projections 166 which are securely fitted into the opposite enlargements 168 of an opening 170 in a ring 172. The internal projecting wall portions between the enlarged portions of the opening 170 are threaded as indicated at 174 with these threads forming a continuation of the internal threads of the tube 162. The ring 172 has a lug 176 which when the parts are assembled as shown in Fig. 17, fits into a small portion only of the semi-circle between the ends of the flange 160 as shown in Fig. 15. The hub 158 contains a small hole 178 in which one end of a coiled spring 180 is placed, theother end of this spring being placed in a small hole 182 formed in the ring 172. The gear 152 together with its hub 158 are thus connected by means of the spring 180 with the ring 172 to which the internally threaded tube 162 is secured. Therefore when the gear 152 is rotated-in the forward direction, the ring 172 and tube 162 will be rotated by the torque action of the spring 180 holding lug 176 against flange 160. However, if resistance to the rotation of the ring and tube is encountered, the spring 180 will be wound under additional tension without rotating the ring and tube due to the lug 176 moving in the opening 161 formed in the flange 160.

he movement of lug 176 in space 161 pro vides the equalizing effect to form an accurate aligned steady guide to move longitudinally under uniform pressure controlling the cutter shaft and cutter head in operation, and forms an important part in the invention. Referring now to Figs. 4 and 10, the manner in which the device just described is used in connection with the guide members 154 will be understood. The inner end of each guide member is hollowed out and the parts just described are placed in the recess thus produced except-that the-upper wall of the guide member is cut away sufliciently to provide for engagement of the gear 152 with the teeth 150 of the ring gear 148 when the guide member is in retracted position. A bearin 182 is provided for the head 164. A bolt 18.4 is secured in the guide member 154 and the threaded end portion of this bolt engages the threads in the tube 162. It will now be understood that when the four gears-152 are rotated forwardly by turning the rod 134,

the four guide members 154- will be moved outwardly in unison. In order to use the expanding, equalizing, contrivance for a centering device, it must be moved from the position shown in Fig. 4 down into the top of the cylinder which is to be finished as shown in Fig. 6 in which view the guide members 154 are shown as having been moved outwardly to center the machine with respect to the cylinder to be rebored. During this initial centering operation the cutter is kept in its inactive position of Fig. 9. As a means for moving the sleeve 88, andhence the centering and cutting devices, upwardly or downwardly with rapidity, a handle 202 (Fig. 12) is connected with a transverse shaft 190 by means of a sliding clutch collar 192 splined to the shaft. When the handle is rotated a pinion 188 on the shaft engages the rack 186 previously referred to and hence raises or lowers the sleeve 88.

With the centering device lowered into the cylinder, its guide members 154 are expanded by means of the rotatable rod 134 until they strike snugly against the cylinder wall. The screws 52 are then tightened to clamp the machine solidly to the cylinder block. By rotating the rod 134 in the reverse direction, the guide members 154 are disengaged from the cylinder wall and the sleeve 88 is then raised until the cutter becomes accessible through the aperture 132. If the cutter has not previously been set to the size desired, this is now done. In either case, the tool carrier is swung on its pivot 104 until it rests against the shoulder 106. All is now in readiness for the start of the reboring operation.

The mechanism for advancing the cutting and centering devices through the cylinder to be rebored is indicated in Fig. 12. For this operation the clutch collar 192 is moved longitudinally so as to disengage the handle 202 and to engage clutch teeth on a worm wheel 206 which is loose on the shaft 190. The worm wheel is rotated by a worm 208 (Fig. 1) on a shaft 210 which is coupled by worm gearing 60, 212 (Figs. 2 and 12) with the motor shaft 58. 'As the shaft 190 is continuously rotated by this mechanism, the sleeve 88 is caused to descend, carrying with it the cutter shaft, the cutter, and the centering device. The centering device is initially but of contact with the cylinder wall, having been backed off as soon as the initial centering has been accomplished. When the sleeve has descended so as to bring the guide members within the cylinder, as in Fig. 6, the rod 134 is turned so as to expand the guide members outwardly into engagement with the cylinder wall. .They are retained in this expanded position by the engagement of the toothed members 138, 140. It will be observed that during the initial part of the reboring operation ample guiding of the tool is provided by the sliding of the enlarged portion 92 of the sleeve in the bearing As the guide member-sled are expanded (which may he done during the continued cutting movement of the machine) of the cutter is over by them, The guide members travel in the freshly cut portion f the cylinder, so that :a straight and true hole independent of initial irregularities of the cylinder wall is as cured. 3o claim:

'1. lln a machine for reboring cylinders, the comhinutionof a cutter shaft, a frame, a support for the movable in the frame in direction axially of the shaft, a cutter on 15 the shaftnuenns for rotating the cutter a centering head carried by the supportend having radially movable guide memhers therein and mounted coaXi-ally wi and closely adjacent to the cutter head so as to so follow it during its cutting movement, means for feeding the cutter and the centering head in the direction of their common axis, means for the centering head against rotation, menus operalole from a point out- 25 side the cylinder in all operative 3 ositions of the cursor head for adjusting the guide members radially during the cutting movement of the head, last-named means including o manually operable member remote from 3% the cylinder and positioned on said supygort. in a machine for reboring cylinders, the \comination oi a sleeve, means for holding the sleeve ngainst rotation and the sleeve in a direction coaxial "with the cyl- 5 inder to he rebored, feeding mechanism for advancing and retracting the sleeve in fire ding means, a cutter shaftroraeahle within the sleeve hut against move- 4 meet therein, a single cutter lined upon the 4D shaft beyond the sleeve, a plurality of radially adjustable M members mounted upon the sleeve adiacent the cutter so as no follow it during its cutting movement, means,

for rotating the cutter shaft during its agxiai movement, and means for adyustlng "the radial position of the guiding members simultaneousiy during the rotative and reciprocating movement of the cutter shaft.

3. In a mac n e for reboring cylinders, 59 the combination of a sleeve having an enlarged' portion adjacent its lower end, means for both the body of the sleeve and the enlarged portion thereof in a direction coaxial with the cylinder to be rehored, feeding mechanism 'for advancing and retracting the sleeve in the guiding means, a cutter shaft rotatable within the sleeve hut fixed against axial movement therein, a cuttor fixed upon the shaft beyond the enlarged portion of the sleeve, a plurality of radially adjustable members mounted upon the sleeve adjacent the cutter so as to follow it during its cutting movement, means for rotating the-cutter during its axial movement, and means for adjusting all the guide members radially and simultaneously during the rotative and reciprocating movement of the cutter and while the cutter is guided by the interaction of the enlarged portion of sleeve and its guide.

1. ln a machine for rehoring cylinders, the comhin ation of a cutter shaft, means for retating the cutter shaft, a centering head havradially mo able guide on, a support for the centering head holding it coaxial with and adjacent the cutter head so as to follow it without rotation the cutting movement, means for the cutter and the centering head in the direction of their common a rod jonrnaled in the centering headnnd parallel to the cutter shaft, and mechanism coupling the rod to the guide members arranged to move send members racially simultaneously upon rotation of the rod irrespective of the rotation of the cutter shaft or of the position of the centering head within ficylinder.

in a machine for the bore of cylindersflhe combination of a base adapted to he supported on a cylinder block, a cutter mounred on e hose, mechanism for operatthe cutter in the here of a cylinder, e holding device adapted to Toe ins rted in the bore of cyli der ihe cylinder to he finished, a plurality of radially movable members earned by said device each cvlinder wall engaging surfaces and lugs ad-apred to nroi'ect beyond the end of the cylinderhore, means for expanding the memsustain the weight 'oi the device one preven: it from dropping the lugs eiiord a anchor an upward null, and clumping means for securing the holding device to the hase.

ii, a machine for finishing cylinder hores in a multi-cylinder engine block-comprising base adapted to rest.- upon the engine hlocli and having a mounting for a tool, an anchor device expa "vely securahle a cylinder here other than the one worked up on and having a plurality of radially movalole members with. surfaces adapted to engage the cylinder wall and lugs adapted to project beyond the end of the cylinder here so as to resist an upward pull, means for expending the memhers whereby their en gaging surfaces sustain the weight of the anchor device and prevent it from dropping, a member vertically adjustahle upon said anchor, and clamping means engageahle with the base and with said vertically adjustahle memher and acting against said lugs whereby the base will he firmly secured to the engine block.

ners'wnerehy wall surfaces Elli) the walls of a cylinder other than the one being worked upon, said members having projections ,engageablebeneath the end of the cylinder wall to resist an upward pull, a member vertically adjustable upon said anchor, a pressure member having intermediate its length a pivotal engagement with said vertically adjustable member and having at one end engagement with the base adjacent the tool mounting, and clamping means operating upon the second end of the pressure member to cause its first end to press against the base with the vertically adjustable member serving as a fulcrum.

8. In a machine for reboring cylinders, the combination of a frame, a rotatable cutter shaft, a cutter carried thereby, a sleeve surrounding the cutter shaft, means for advancing the sleeve and cutter shaft through the cylinder to be rebored, means on the frame for guiding the sleeve during at least a part of its advancing motion, an expanding nonrotatable guide mounted on the sleeve to the rear of the cutter but closely adjacent to it, and devices operable from a point outside the cylinder and during the continued motion of the cutter'shaft for expanding said guide into contact with the freshly cut cylinder Wall.

9. A device for securing a tool to a multicylinder engine block comprising a base adapted to rest upon the blockand having a mounting for a tool, an anchorhaving a lug projectable beyond the end of the wall of a cylinder other than the one being worked upon, said anchor with the lug thereon being adapted to pass freely through the cylinder bore, means associated with the anchor operable by contact with the cylinder wall to project the lug into extended position beyond the cylinder wall, and clamping means for drawing the anchor towards the base whereby the base will be clamped to the engine block by the engagement of the lug with the end of the cylinder wall.

10. A device for securing a tool to a multicylinder engine block comprising a base adapted to rest upon the block and having a mounting for a tool, an anchor having a lug projectable beyond the end of the wall of a cylinder other than the one being worked upon, means contacting with the cylinder wall at the opposite side of its central plane to hold said lug in projected position, a member pressed against the interior surface of the cylinder on the side adjacent the lug by the action of said means to hold the anchor in the cylinder against dropping, and clamping means for drawing the anchor towards the base whereby the base will be clamped to the engine block by the engagement of the lug with the end of the cylinder wall.

ll. A method of boring with a minimum eccentricity and with a minimum of deviation in axial direction the cylinders of inter nal combustion motors or the like, which comprises carrying a cutting tool through a helical path, guiding the cutting tool from a point outside the cylinder during the initial portion of its travel so that it moves in a truly cylindrical surface, passing a guide member into the freshly cut portion of the cylinder, expanding the guide member into contact with the freshly cut portion of the cylinder without interrupting the continued helical motion of the cutting tool, and completing the boring of the cylinder with the tool guided by said guide member from the cut surface of the cylinder.

In testimony whereof I hereunto affix my signature.

EWALD A. ARP. 

